The presently disclosed subject matter relates to a luminal cavity closing device and a method/treatment for closing a luminal cavity (e.g., a hollow pouched structure having a lumen with an opening, including structures such as an aneurysm or varix or left atrial appendage or the like, hereinafter generically referred to as “luminal cavity”) generated in a living organ or tissue.
A part of a blood vessel that is locally dilated and weakened is called an aneurysm or varix, and, particularly, one that is generated in an artery of the brain is called a cerebral aneurysm. Rupture of the cerebral aneurysm can cause subarachnoid hemorrhaging. There are several therapeutic methods for preventing such a rupture. One of the methods is the “neck clipping technique” in which craniotomy is conducted neurosurgically, and the portion between the cerebral aneurysm and the parent artery (a base portion of the aneurysm) is clipped. Another one is a method referred to as an “embolization technique,” in which treatment is carried out without craniotomy. In this method, a catheter is inserted into the cerebral aneurysm via a blood vessel, and a flexible coil formed of a metal such as platinum is guided through the catheter and embedded in the cerebral aneurysm.
In accordance with one example of an embolization technique, as shown in Japanese Patent No. 4060528 (hereinafter referred to as Patent Document 1) and U.S. Pat. No. 7,128,736 (hereinafter referred to as Patent Document 2), an opening of a luminal cavity continuous with a blood vessel may be occluded, after an occlusive agent or a cage (corresponding to the above-mentioned coil) or the like is embedded in the luminal cavity (or without conducting such an embedding step). Incidentally, the expression “occlude” herein includes, unless otherwise specified, not only the meaning of a tight closure of the opening of the luminal cavity but also a concept of leaving part of the opening open without completely closing the opening, a concept of covering the opening with a meshed member, and the like concepts (in other words, the meaning of occlude includes operations related to blocking an opening so as to restrain the flow of blood through the opening into the luminal cavity).
For instance, in the case of the luminal cavity closing device disclosed in Patent Document 1, a device (lid member) having a shape memory structure capable of deployment (expansion) into a dish-like shape in a luminal cavity is delivered, and the lid member is disposed in the manner of bridging a neck (opening) of the luminal cavity, thereby occluding the luminal cavity. On the other hand, in the luminal cavity closing device disclosed in Patent Document 2, a mesh-formed lid member extending radially from a central portion is disposed at an opening of a luminal cavity, thereby occluding the luminal cavity. With the lid member disposed in this manner, the flow of blood into the luminal cavity is restrained.